1. Technical Field
The present invention relates to a liquid ejecting head in which liquid is ejected from nozzle openings and a liquid ejecting apparatus.
2. Related Art
An ink jet type recording head which includes a head main body in which a pressure generation chamber communicating with a nozzle opening through which ink droplets are discharged is deformed by a pressure generation unit, such as a piezoelectric element, in such a manner that ink droplet is discharged through the nozzle opening and a flow-path member which constitutes a flow path of ink supplied to the head main body is known as a liquid ejecting head.
In a case where a plurality of tributary flow paths which communicate, via bifurcation points, with mainstream flow paths having a common ink-supply source are provided in such an ink jet type recording head, it is necessary to set discharge properties of heads as same as possible by reducing variation in pressure losses in the tributary flow paths. Here, technique in which, when ink is supplied to a plurality of heads through supply tubes having a bifurcation function, the cross-sectional areas of the respective supply tubes change in accordance with the distances from a liquid storage unit to the respective heads has been disclosed (see JP-A-2011-88400).
However, in the configuration disclosed in JP-A-2011-88400, basically, a tube is used as the flow path. Thus, the cross-sectional area of the entirety of the flow path changes. Accordingly, a problem in relation to the connectability of the flow paths or variation in flow velocities in the respective flow paths is not considered, and thus the problem in relation to the connectability of the flow paths or variation in flow velocities in the respective flow paths cannot be solved. In addition, a problem that the size necessary for the flow path increases in accordance with an increase in the number of bifurcation portions is also not solved. Furthermore, there is no particular mention in relation to a supply pressure with respect to the mainstream flow path. In some cases, a problem that, in a tributary flow path in which the flow velocity is small, it is necessary to extremely increase, for example, the supply pressure with respect to the mainstream flow path, in order to ensure adequate air-bubble discharge properties is caused.
Such a problem is not limited to an ink jet type recording head but shared by a liquid ejecting head unit which ejects liquid other than ink.